I personally would recommend the 3" downpipe. You will not lose much, if any, torque and you'll make up for it in top end. Also, if you keep modding, a 2.5" DP will become a restriction... just FWIW.

I had the HV3, it's nice and all but not sure if it's worth the price. It's 30 hp at 5800 rpms so you will notice a BIG increase in top end, but you won't notice any increase in daily driving.

If you're getting 2 grand to play with, if it were me, I'd be ordering an SS M90 kit the next day.